Is it possible? Yes. Do I have experience of modding Paradox games? Yes. Do I, or anyone else, have the hours and hours of time it would take to convert a BM map to CK2 and scale them? Probably not.
However, this is a good idea and something that I will have a wee look into to see how modding would work for CK2 for reference purposes. Not least because when BM eventually dies it would be good to have an equivalent which people could play. I can imagine, for instance, that a multiplayer game on an EC sized map where every region lord is a player would be particularly interesting and fun. Though as a singleplayer game it probably wouldn't be anything special.
